How to Diagnose and Fix Flow Issues in Gaggia Classic Machines

Even the most high-quality machines run into issues from time to time. If you’re experiencing flow problems with your Gaggia Classic, Classic Pro, or Evo Pro, this guide will walk you through how to diagnose and fix some of the most common issues. 

If you follow this guide carefully, you should be able to resolve most flow issues on your own.

Table of Contents

Step 1: Do a Flow Test

Before you can complete a home repair of your Gaggia machine, you need to figure out if what you’re experiencing is actually a flow issue.

The video below will walk you through the process of conducting a flow test on your Gaggia machine. 

A properly functioning machine will have a flow rate of about 9 grams per second or a water output of about 3.25 fluid ounces in 10 seconds. If your numbers are lower, you have a flow problem. 

Video: Flow Test

If your machine is outputting at an appropriate rate but you still have another issue, go back to our support page for more help diagnosing what your issue might be. 

If you do have a flow problem, the next step is to diagnose what might be causing that problem.

Step 2: Diagnose Your Flow Issue

Flow issues can be caused by a wide variety of problems, including a bad pump or clogs in the hydraulic system. 

The video below will walk you through steps you can take to help figure out exactly what’s wrong with your machine and how you can fix it. 

Video: Diagnosing Flow Issues 

Common Causes of Gaggia Flow Issues:

Most of the time, if your Gaggia machine isn’t flowing as it should, it’s because of one of the following reasons. Click on the links below to jump to an article or video that will help you resolve the specific problem you’re experiencing.  

Descaling Clogs: 

During the descaling process, chunks of scale can break loose and clog the three way solenoid valve. This article will show you how to clean three three way solenoid valve.

Descaling your machine on a regular basis will help prevent significant scale build-up, so your machine will be less likely to clog. How often you need to descale your machine depends on how hard your water is, though every 90 days is a good rule of thumb for standard, everyday use.

We also recommend using the BWT Bestsave S Anti-Scale Filter for additional protection against scale buildup. 

Water Intake Line Misaligned

When removing and replacing the water reservoir, it’s possible for the water intake line to become bent upwards so it sits above the water level. This prevents water from being drawn from the reservoir. 

Here’s how to perform a  reservoir tube check.

Brewing Components Clogged

After repeated use, coffee can build up on the brew group and shower screen, shower holding plate, and the filter basket(s) which may restrict flow. 

Here’s how to perform routine group head cleaning and maintenance.

Coffee is Ground Too Fine 

If you’ve ground your coffee too fine, it could become too compact and restrict coffee flow. 

Here’s a helpful guide on how to fix your espresso extractions.

Pump Failure

If you’ve been putting your machine through its paces for a while, you may need to replace the pump. 

Here’s an easy-to-follow process for how to diagnose and replace your pump.

Boiler is Clogged

If you’ve descaled your machine and it continues to clog, it’s possible that you have scale buildup in the boiler itself. If this is the case, scale from the boiler will make its way into other lines in your machine, which can cause blockages. 

Here’s a detailed explanation of how to access, clean, and (if necessary) replace your boiler

No Flow Through the Steam Wand 

If you’re not getting good flow through your steam wand, the first step is to check for a clogged steam tip. If your wand tip is clear, you may need to replace your steam valve in order to restore flow. 

Here’s a guide on how to replace the steam valve.

Set Up a Repair

We know—espresso machines are complicated. If you’ve given it a shot and can’t figure out how to fix the issue, we’ve got your back. 

Setting up a repair with one of our skilled technicians is as easy as clicking here.  

Warranty Disclaimer: Failure of normal wear and tear items such as group gaskets, seals and shower screens are not covered under warranty.  Issues due to scale build up or lack of maintenance are not covered.

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